| Author | Message | ||
     Lars1974 |
Hi all, as you may have read in one of my previous threads - I have now got a half stripped REAR spark plug thread - which requires repair on my 06 Uly. the previous owner must have cross-threaded the old plug as i never had them changed yet. we did get a new one install - but with only half of the thread holding it in place its not ideal! I am aware that either Time-sert or Heli coil is the best repair on the rear cylinder head. Now I have never done such a thing and although the re-tapping of the thread seems to be a not too difficult procedure - I am worried about the access to get to the cylinder head. I believe its best to take the head off the engine and than work on it as otherwise there is a risk of some metal shavings getting inside the engine - which I want to avoid of course. I have read that you can rotate the engine down in a Uly, but I dont think this will give me enough access to remove the cylinder head. So i guess I would need to drop the engine out completely - Am I right? This looks like it will be a major operation and I am not even sure if I should attempt this myself. What other option do i have, if any? Looking forward to your advise. thanks Lars | ||
| Nillaice |
Bum luck on those stripped threads. Good on you for fixing it right. I've always found plenty of time to fix things the right way the second time around. Get the manual. It will answer your questions and provide detailed instructions with pics and torque values. There are many ways to get it, and its not much $ for its worth. Rotating the engine down should give you sufficient access to the rear head. But having the engine removed and on a bench stand would, of course, be ideal. | ||
| Ratman |
Talk to a auto repair shop that works on Ford/Triton engines. Their well known for blowing spark plugs out and there are a couple kits available to repair them. They might be able to provide a easier and less costly fix than a tear down | ||
| Hughlysses |
Since you do have SOME threads left, it would certainly be worth trying the Loctite thread repair kit. Basically, this is some super tough, reinforced epoxy that is specifically engineered for thread repairs like this. You clean the whole, mix up the epoxy, and goop it in the hole. Then you apply a release agent to the male threads (spark plug in your case) so the epoxy doesn't bond to them before it sets up, and screw the plug into the hole to form the threads. Wait until the epoxy hardens, then torque the spark plug down. The stuff is supposed to be good for 128 ft-lbs, which is way more than enough to hold a spark plug. Here's one place you can get it: http://www.amazon.com/Loctite-Form-A-Thread-repair -kit-grey/dp/B000WSEUII The worst that could happen is it won't hold, in which case you won't be any worse off than you are now. If it does work, you'll save yourself a whole lot of work. | ||
| Reepicheep |
LOL! I have an absurd amount of relevant experience on this thread.  1) You can pull either head off a Uly easily once you rotate the engine. Tons of space, easy to do, just pricey with all the new gaskets. If the head is off, you might as well replace the base gasket as well. 2) I helped a buddy repair a Ford engine in an F150 that blew out a spark plug. He got a nice kit for some chunk of change that included the drill bit and stops and inserts to do the whole repair with the head in place. Massive PITA on the Ford motor with that deep head, it would be much easier on a Uly motor rotated down (even with the head in place). The kit was pricey, but not insane, and it had everything you need. That exact kit would probably work for the Uly engine with some care and tweaking (if the spark plug threads and size are the same). 3) I tried the thread repair epoxy on a dirt bike (not for a spark plug) and it was a joke. Maybe the batch I got was bad, but it would barely hold past finger tight. Expensive and worthless. I think the stuff I had was that Loctite linked. While on one hand it's not hard to pull the head, on the other hand, with a lot of compressed air and shop vacs and various tubing and duct tape with a borrowed bore scope, many Ford owners are doing this without removing the heads and it turns out fine. And finally, you might be able to find a whole good rear head for $200. For what that's worth. (I did that too... ) | ||
| Teeps |
I would not use epoxy or other voodoo repairs on a spark plug thread. I would not hesitate to install a Time-Sert with the head on the engine. I have done such repairs hundreds of times, with no problems. (I was a m/c mechanic back in the day.) I've used both Time-Sert and Heli-Coil; but I prefer the former if available at a cost effective price. This kit requires no special tools other than a way to turn the tap and setting tools. https://www.belmetric.com/ts4412-m14x125-sp-kit-p-1601.html?zenid=854nvo5e20fn52qq3cgq1mciu6&cPath=217_220_262 (Message edited by teeps on April 24, 2013) | ||
| Garrcano |
IIRC our spark plugs are M12 with a 19 mm thread length. | ||
| Lars1974 |
Thanks guys for the tips. I do need to check first that I have all the tools before I start such an operation... I do have the workshop manual which is a start and i do have a garage with enough room, but never done than basic maintenance. We shall see... | ||
| Desertjeff |
I second Teeps Time-Sert recommendation. They work great Heli-Coils work ok too although I have had trouble breaking off the little tab after installing them. I use lots of grease packed into the flutes of the drill and the tap to help collect the metal chips. Insure both valves are closed in the cylinder you are working before drilling or tapping the spark plug hole. Bent valves are a near certainty if you fail to do so. | ||
| Lars1974 |
Hi guys, I took a picture of the spark plug in question....as you see the thread damage has been almost half of it!  There was more thread on the plug and also what we hoovered up before install a new plug for now.... Anyway i will keep you posted. But time sert will be what i will get. Thx for all the advise. Lars | ||
| Lars1974 |
ok, i can use our workshop from my office - which is a first step in the right direction - as we have tool and bench and engine hoist / lifts etc... i guess i will take the cylinder head off to do the time sert repair. So now i need to go shopping as i need: = right time sert kit (i believe 12mm x 1.25) = relevant gasket for the repair - including cylinder bottom gasket is there a kit for this gasket set? | ||
| Nillaice |
HD rockerbox gasket kit http://www.badweatherbikers.com/buell/messages/384 2/545648.html?1363722436 you'l still need to buy the HD head gasket or cometic makes a top end kit Stock Code: C9204 Price: $106.18 i'd call and talk to someone to make sure its the right kit before placing an order | ||
| Teeps |
I stand corrected the plug is 12mm not 14mm. I should have looked at the plugs in my tool box before typing, sorry about that... Appears the tool may be a little cheaper too for 12mm, if you can use the standard tool. | ||
| Reepicheep |
You can defer the head decision. Leave it on, make sure the valves are closed, drill and tap and hit it with about a billion cubic feet of compressed air at 11ty million pounds, then decide if you really need to take the head off. Maybe borrow a borescope. I bet if you did that, you would decide not to pull the head, and that it would be fine. | ||
| Mnrider |
NAPA auto parts sells a kit with everything you will need to do it on the bike. google napa sav-a-thread. I've repaired dozens of spark plug holes on Ford triton engines with no problems. | ||
| Lars1974 |
Thanks again guys for the pointers... i did some searching and i think this link below show the correct time sert kit i need??? http://www.ebay.co.uk/itm/TIME-SERT-NEW-4212-M12X1 -25-Spark-Plug-Thread-Kit-/281097445923?pt=Motors_ Automotive_Tools&hash=item4172b6a223#ht_3670wt_120 5 or am I wrong? Thanks Lars | ||
| Uly_man |
Looking at that plug it may be that its been blowing past the threads and given that you can only "cross thread" from the start of the threads it looks bad. That swarf on the plug is whats being cut away from the top of the cly as you pull it out due to the damage on the threads. If it was me I would do what Reepicheep says. Access is tricky and you will need to take your time to do it right. Good luck. | ||
| Lars1974 |
Given the fact that i did already almost 100 miles with the new plug in place...i may chance it for now and go for a spirited ride tomorrow and see if the plugs stays where it should be... The worst that happens is that it blows out and than i need to do the repair anyway... | ||
| Johnshore |
I bought a used Uly with only 2500 miles. The only maintenance he had done was replace the plugs. I found out they were both stripped when the front plug blew out. It ran amazingly good on one cylinder the five miles home, even idled correct. Just loud. I used the time cert and its been good for 15000 miles so far. I rotated the motor and the front plug was easy. To do the rear plug I had to use a wrench because there was no clearance for the ratchet. I used a lot of grease on the tap and cleared the chips often. Gave it a blow out when it was done. I think the Uly was built by Buell just for me. |
